Electrolytic Rust Removal

[SuperDave]

How could I fiddle with old, rusty Z's for 15 years and not know about Electrolytic Rust Removal? Someone else mentioned it here, I Googled it and studied these articles:

Electrolytic Rust Removal

http://www3.telus.net/public/aschoepp/electrolyticrust.html

http://www.buchanan1.net/rust.shtml

Electrolysis Rust Removal

http://www.htpaa.org.au/article-electro.php

The process was cheap, didn't require any nasty chemicals, didn't produce any nasty chemicals, and seemed to produce good results, and since I have no shortage of old rusty Z parts lying around, I decided to give it a try.

I went to the grocery store and bought a box of washing powder, which is simply sodium carbonate. Some of the sites say you can use baking soda (sodium bicarbonate) but I didn't find any articles where anyone had tried it. Basically, all the sodium carbonate does is make the water conduct electricity better. Then I bought a sheet of 22 gauge steel from the hardware store (it must NOT be galvanized/zinc coated). Some people use rebar. Don't spend a lot of money on your electrode--it will eventually get eaten away in this process. Also you don't want to use stainless steel because it can create hazardous insoluble hydroxides or oxides. I filled a 5-gallon bucket with water and pulled out the battery charger. Then I selected a nicely rusted brake rotor.

I put roughtly 5 tablespoons of washing powder in the bucket and stirred it up. I bent the steel sheet to fit the curve of the bucket and inserted it so that a few inches stuck out above the water. I put the rotor in the bucket so that it was a couple of inches away from the steel sheet. The rotor just barely fit in the bucket, so I was sure it wasn't going to move. Later I clamped the steel sheet to the side of the bucket.

I moved all of this outside to the garage stoop. You want to do this in a well ventilated area because this process is going to release pure oxygen and hydrogen. Don't smoke around this! I left the battery charger just inside the garage door and stretched the leads outside so I could hook the battery clamps up to the rotor and the steel sheet.

I checked the article once more before I switched on the charger...GOOD THING! Did you catch what is wrong in the picture above? I reversed the wires! You want to put the NEGATIVE terminal on the rusty piece and the POSITIVE terminal on the steel sheet or electrode. If I had left it this way for very long, my positive battery charger clamp would have gotten eaten away. You want your rusty piece to be submerged in the water and it's ok if your (negative) charger clamp is partially submerged. You don't want your positive charger clamp on your electrode (steel sheet) to be under the water.

I put the charger on 6V and plugged her in. Immediately it showed a 2 amp draw. In just a minute bubbles started rising off of the rotor and the steel sheet. The bubbles coming off the rotor are hydrogen and the bubbles coming off the electrode are oxygen.

I left it outside overnight. When I checked it in the morning the water had turned rust-colored and had rust-colored foam on top. I unplugged the charger and unclamped the leads.

I looked at the steel sheet. It was covered with thick black stuff--oxide. I pulled out the brake drum, hosed it off and scrubbed it with a plastic brush. Then I dried it off with a paint dryer. Sure enough, the rust was almost completely gone! Almost, but not completely. So I pulled out my drill/wire disc and worked on it. It didn't take much effort at all to make it shine. Now, it looked a lot better!

It still looks a little darker than you'd expect brand new steel to look. I think part of that is from oxidation in the process. The amazing thing is that it seems like every flaw in the rotor now stands out like a sore thumb.

My now-rust-free rotor is now extremely rust-prone so I applied some Sherwin Williams Ultra Clean and later I might shoot some WD40 on it.

My rotor is rust-free on only one side. This process only removes rust for the parts of the rotor that could "see" the steel sheet. This is because the electrons take a direct path from the electrode to surface of the rusty piece. I'll have to turn the rotor over and treat the other side.

Overall, I'm pretty pleased with this process and I'll use it on as many parts as I can. I want to do some more research before applying this to stressed parts like suspension pieces. I've read that this process can cause hydrogen embrittlement--some of the hydrogen goes into the metal. It's possible that the hydrogen can be released by baking the piece afterwards for a few hours in a 200-degree oven, but don't take my word for that. And I'm assuming you don't want to even think about doing this for internal engine parts.

Next, I have an incredibly rusty oil pan I'm going to treat. Also, I'm going to figure out how to set up the old plastic kiddie pool to de-rust larger parts.

And if I can just figure out who will let me drive my stripped chassis into their swimming pool and how much washing soda it would take to treat my entire car...

[gmjanssen]

Actually I had seen a site where there are places that will dip the whole body of the car in a tub for this process. It takes a day or two, but the end result is that the rust is removed from the impossible areas that will wind up rusting out cuz you can't get to them. I have looked around Virginia a little for a place that does this and so far no luck. But I am still looking.

[Bambikiller240]

26th-Z has his car at a Spa in FL having this process done to HLS30-0026.

See:

http://www.classiczcars.com/forums/showthread.php?t=11509&highlight=SPa

[SuperDave]

26th-Z has his car at a Spa in FL having this process done to HLS30-0026.

See:

http://www.classiczcars.com/forums/showthread.php?t=11509&highlight=SPa

From the thread Bambikiller240 mentions...

The car will be placed on a cradle and lowered into a tank full of degreaser and paint stripper for approximatley two weeks. Then it will be pressure washed to remove the seam sealer, insulation, glue and other goo. This process does not harm the lead filler or some of the plastic coatings like around the wiring harness ties. Then the car is submerged in the alkaline solution and de-rusted.

Yes, I believe the alkaline dip is similar to electrolytic rust removal. But that's the last of several steps.

That reminds me that I didn't mention that you're supposed to have the rusty part free of grease and oil. So that's what the degreaser and paint stripper will do for 26th-Z's 26th-Z.

I envy him. He's doing it right!

[Zedrally]

If you have gone to the trouble of electro stripping rust from body parts, have you considered either galvanising or copper plating the parts?

This would solve the problem of concealed ares becoming vunerable to rust and could possibly be the ultimate solution?

MOM

[26th-Z]

Serious thanks for going through all the trouble to write that piece!

That right there, ladies and gentlemen, is exactly what I am up to for rust removal during the restoration of my cars. A degreaser / paint remover is used to strip the part clean. Then the solution I have been describing as alkalyn is used for the electrolytic process.

Great discussion and excellent references.

[hls30.com]

But, look what it did to your car!

After cleaning, it is plaiting, only backwards!

brilliant!

Will

[zguitar71]

The process is the rverse of Hydrogen fuel cell. Place a thine membrain of platinum between O2 and Hydrogen and you get electricity. Well it is close to the reverse, you do ot have and pltinum in your process.

Could you use two chargers and place an electrode on both sides of the rusty peice to remove the rust on both sides at once? Can the process be done in a metal bucket?

[SuperDave]

I've done half of the oil pan from my parts car. I had thought it was junk, but now maybe it's good enough to keep as a spare. The left side is the part that stuck up out of the solution and thus hasn't been treated yet.

Can the process be done in a metal bucket?

Absolutely you can use a metal bucket...uh...but eventually your metal bucket would get eaten away.

have you considered either galvanising or copper plating the parts?

No...I don't know anything about how to do that. Do you? What benefits would it give? How hard is it? The thing I like about the electrolytic rust removal is that it is so easy, cheap, and (usually) environmentally friendly.

This would solve the problem of concealed ares becoming vunerable to rust and could possibly be the ultimate solution?

I don't think this is the ultimate solution for concealed areas because the part has to "see" the electrode to get its rust removed. Notice on the oil pan above that the bottom of the sump didn't get as clean as the sections that were closer to the electrode. I guess this is because it didn't get as many electrons shot at it as other parts of the pan either because the sump didn't "see" the electrode as well or becuase it was further away from the electrode.

26th-Z...I'd love to see more pictures of your dipping. I had thought it was just one acid dip that ate away paint, grease, rust, everything, but it's different from reading your info. You know, for $1,000-plus you could put a down payment on a pool and do it in your back yard!

[hls30.com]

Getting the pool would not be the problem, keeping the neighbor hood kids out would be. Seriously when you get ready to change the fluid, or move the pool, what do you do with the leftovers-it will be caustic from all of the removed solids, and the chemical breakdown of the original mix-if it never changed chemically, you would never need to freshen or replace it, and you will. Look at how the fluid has changed with the few parts you have done already. A gallon or two won't get noticed in a storm drain-not that I am saying that is where to put it. But a couple of hundred gallons would interest your city/county/state government, and make you a target for anything else you did that the neighbors missunderstood/didn't like, one call that's all.

Will

[26th-Z]

Hello Dave - everyone! Nice conversation! Great job on the oil pan.

The place I am using is called Revivations and they are in Wauchula, Florida. (You should have seen the town after the hurricanes got through with it). They have a big metal building with two fiberglass tanks and a big rolling chain hoist down the center. The floor is drained for liquid recovery. Cars are brought in on fork lifts and set in the hoist baskets. The first tank is some sort of water soluble paint stripper solution and the car sits in the tank for around two weeks. Then it is pressure washed with hot water and inspected. If more crap needs to come off, it is dumped back in the stripper tank. Otherwise, the car is submerged in the electrolytic tank for several days. I think they rotate the car in the tank a couple of times. After it dries, they blow the car with high pressure air. There is about a six week time frame to seal the metal up before it starts rusting again. This process does not harm plastic or the lead fillers in the body shell.

My avatar is Her Majesty the 26th sitting in the field net to the metal building. She should be back in March and I am spending $1,400 for the body shell. I may take the doors, fenders and such depending on what my bodyshop guy thinks when we get to that point. I had a wheel cleaned by them and I had them strip a set of hubcaps before I sent them off to be re-chromed. Electrolytic is the way to go as far as I am concerned. I'm lucky to have this place so close.

Try cutting down a plastic 50 gallon drum to use for a tank and experiment with the size and placement of your anode (?) sheet of steel. Make sure the solution concentration is correct. Try rotating your pieces and leaving them submerged for different periods of time. The cleaner the piece is before the electrolytic process, the better the results. Even though the piece may not be in direct sight of the anode (?), the derusting process is still happening. Just at a slower rate. Direct sight is important, but the process is still working. The acid dipping process is what the hydrogen in the metal controversy is all about. Not the elecrolytic process. Long exposure to phosphoric acid is what makes the metal brittle.

Even though the plating process is the same as this in reverse, different solutions are used. Eastwood sells kits for plating, including a kit to plate in the golden cadmium / zink for our Datsun hardware. I think the kit is too expensive. I'm sending my stuff out. I think this IS the ultimate solution (no pun intended) because it will get the rust completely out of the body shell. The trouble I have with 26 is inside the shell structure. She is rusting out from the inside.

Now, I don't know where you all live, but in Sarasota, $1,000 is barely enough down payment for a small hot tub.

[gmjanssen]

I agree with all above. I have a November 1971 manufactured 240 and my goal is to restore it once to last for another 33 years. I might even put it in my will to be buried in it like that lady did with her caddy (?) out west. I swear, if the Surgeon General knew of the addictive nature of zeds he would've put those warnings on the quarter panels like a pack of smokes!